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3 years ago

If someone sees this, can you kinda run thru it in a reply. Its solve using elimination btw.

Mathematics

1 answer:

Nataly_w [17]3 years ago

7 0

See the attached picture for the steps and answer.

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Simplify the following expression:<br> 3[(x^3– 7 x + 1) – (x+ 4)]

Alona [7]

Answer:

15 - 9

Step-by-step explanation:

3[( 3x - 7x plus 1) - (x plus 4)]

3[(-4x plus 1) - x-4

3[-4x plus 1 -x-4

3[-4x-x plus 1-4]

3[fivex -3]

fifteen x - 9

5 0

3 years ago

Sin(A+B) sin(A-B) /sin^A Cos^B=1-cot^A Tan^B

telo118 [61]

In order to prove

$\dfrac{\sin(x+y)\sin(x-y)}{\sin^2(x)\cos^2(x)}=1-\cot^2(x)\tan^2(y)$

Let's write both sides in terms of $\sin(x),\ \sin^2(x),\ \cos(x),\ \cos^2(x)$ only.

Let's start with the left hand side: we can use the formula for sum and subtraction of the sine to write

$\sin(x+y)=\cos(y)\sin(x)+\cos(x)\sin(y)$

and

$\sin(x-y)=\cos(y)\sin(x)-\cos(x)\sin(y)$

So, their multiplication is

$\sin(x+y)\sin(x-y)=(\cos(y)\sin(x))^2-(\cos(x)\sin(y))^2\\=\cos^2(y)\sin^2(x)-\cos^2(x)\sin^2(y)$

So, the left hand side simplifies to

$\dfrac{\cos^2(y)\sin^2(x)-\cos^2(x)\sin^2(y)}{\sin^2(x)\cos^2(y)}$

Now, on with the right hand side. We have

$1-\cot^2(x)\tan^2(y)=1-\dfrac{\cos^2(x)}{\sin^2(x)}\cdot\dfrac{\sin^2(y)}{\cos^2(y)} = 1-\dfrac{\cos^2(x)\sin^2(y)}{\sin^2(x)\cos^2(y)}$

Now simply make this expression one fraction:

$1-\dfrac{\cos^2(x)\sin^2(y)}{\sin^2(x)\cos^2(y)}=\dfrac{\sin^2(x)\cos^2(y)-\cos^2(x)\sin^2(y)}{\sin^2(x)\cos^2(y)}$

And as you can see, the two sides are equal.

6 0

4 years ago

Find the value of x round to the nearest tenth

Leto [7]

Answer:

58.6

Step-by-step explanation:

Use the formula $c=\sqrt{a^{2}+b^{2}$

solving for x (b)

$b=\sqrt{c^{2}-a^{2}$ = $\sqrt{61^{2}-17^{2}$ ≈58.58327

and 58.58327 rounds to 58.6

4 0

3 years ago

What is the approximate solution to this equation?

Nookie1986 [14]

Answer:

C. x ≈ 0.28

Step-by-step explanation:

A graphing calculator solution is attached. It shows ...

x ≈ 0.28

You can divide both sides of the given equation by 5, then take natural logs and divide by 5 again.

5e^(5x) = 20 . . . . . . given

e^(5x) = 4 . . . . . . . . divide by 5

5x = ln(4) . . . . . . . . take natural logs

x = ln(4)/5 . . . . . . . divide by 5

x ≈ 0.277259 ≈ 0.28

7 0

3 years ago

brenda's dad measures her height to be 61 1/8 inches. six months later, he measures her height again. he says she has grown 3 1/

Monica [59]

Answer:

9 3/16

Step-by-step explanation:

to add fractions make sure they have a common denominator

3 0

4 years ago